Soil fertility status evolution is a decision making tool for the sustainable soil nutrient management. To evaluate its status, about 29 research data were collected and meta data analysis were made using SPSS for the selected soil chemical parameters. The soil was moderately acidic and salt free, 93.2% of Zinc (Zn), 100% of Manganese (Mn), 100% of Iron (Fe) and 79.3% of Copper (Cu) status were in sufficient range respectively. However, 44.7% of Phosphorus (P) and 72.3% exchangeable Potassium (K) status were found in a low range, 54.7% of organic carbon (OC) and 34.5% of total nitrogen were respectively found in a medium range, while 93.2% CEC was found in high range. The fertilizer recommendation can be done based on soil fertility status to economize crop production. Land use practices in agro ecosystems and plant species significantly influence the nutrient balance in the soil. According to this review, full nutrient balances of N, P and K in southern Ethiopia, across cropping types were (-31, +71 and -169) respectively. Accordingly, for the better crop production applying recommended fertilizers might be an option to replace the lost nutrients. Major crops (wheat, maize, teff, barley and sorghum) have reveled increased grain yield which were economically positive, indicating the potential of soil in the areas were in deficient levels, hence crops showed responses for fertilizer inputs. Therefore, balanced fertilizer use increase crop production and reduce environmental pollution.

Background: Predicting soil phosphorus (P) needs and P fertilizer requirements are important for plant nutrition and reducing environmental risk. Thus, the precise estimation of available soil P (ASP) is required for the better management of environmental resources and improving agricultural productivity. Yearly, direct measurements of most nutrients at large scales are time-consuming and expensive within the economic point of view.Aim: Therefore, to tackle such limitations indirect measurement of them in an accurate estimating manner is a possibility.Methods: Thus, during this study, an exponential regression model for predicting ASP was suggested, and it was estimated as a function of soil organic carbon (OC). OC and ASP were used to investigate and analyze the soil to determine empirical relationships between them. Determination of the mentioned nutrient within the laboratory is somewhat difficult and time-consuming. Therefore, an exponential regression model for predicting ASP from soil OC was suggested, and it was estimated as a function of soil OC. The ASP predicted from the ASP-OC model was compared to the ASP determined by laboratory test using the paired samples t-test and the Bland-Altman approach using SPSS. Results:The ASP predicted by the ASP-OC model was not significantly different from the ASP determined by laboratory test since (p > 0.05). Conclusions:The findings of the study indicated that the ASP-OC model provides a simple, economic, and brief methodology to estimate ASP, and so to predict ASP-supported soil OC using the exponential regression model (Y = ae bX ), the suggested model based on the findings for ASP is ASP = 9.786 e 0.486 OC with R 2 = 0.901 often suggested.

Background: Availability of accurate soil data is necessary in understanding the nature of the soil and its status of the agricultural potential. Aim: Thus, a research was carried out to investigate physicochemical and morphological properties of the soils and characterize, classify and mapping them accordingly at Enemor Ener woreda, southern Ethiopia. Methods: Nineteen (19) representative pedons were opened from lower, middle and upper slopes and described them according to WRB (2014). Soil samples from each horizon were analysed for physicochemical properties. Results: Soils in the study area are so variable in their formation and nutrient availability. The major soil textural classes are clay loam and clay. Calcium the most dominant exch. bases whereas, Magnesium, sodium and potassium follow in decreasing order. The soil pH was ranged from strongly acidic to neutral reaction. Total nitrogen and organic carbons contents in all soils of the pedons are low to very low. Phosphorous content was ranged from optimum to very low content. Cation exchange capacity and percentage of the base saturation were ranged from very high to optimum, in regards to the micronutrients such as iron, manganese, copper and zinc in the soils were ranged from sufficient III to sufficient I.  Major soil types revealed in the study area are Chromic Luvisols, Haplic Nitisols, Mollic Leptosols and Mesotrphic Vertisols. Conclusion:  Soil properties and their potential status influenced by topography and land use type. Therefore, practice of soil integrated fertility management is vital for their sustainability.